[abdus110]

hi just thought id start this thread hws everyone feeling for the exam?? i believe that its better than the S1 but they can throw in the odd question knowing mei but hopefully it should be a good paper whats ever ones thoughts??????

[Fatima0065]

(Original post by abdus110)
hi just thought id start this thread hws everyone feeling for the exam?? i believe that its better than the S1 but they can throw in the odd question knowing mei but hopefully it should be a good paper whats ever ones thoughts??????

Hello im finding it okai..finally getting the hang of it but i need help on the 6 mark questions for commenting on contribuions after contingency..do you know what to points to write???
and when you use the inverse table how do you know wehn the inverse probability is - or a plus...if that makes sense? thanks for starting this therad..i was jsut gona start buh i saw urs

[SugarLips.]

(Original post by Fatima0065)
Hello im finding it okai..finally getting the hang of it but i need help on the 6 mark questions for commenting on contribuions after contingency..do you know what to points to write???
and when you use the inverse table how do you know wehn the inverse probability is - or a plus...if that makes sense? thanks for starting this therad..i was jsut gona start buh i saw urs

(Original post by abdus110)
hi just thought id start this thread hws everyone feeling for the exam?? i believe that its better than the S1 but they can throw in the odd question knowing mei but hopefully it should be a good paper whats ever ones thoughts??????

Hi can either of you explain to me the critical value stuff... and when doing hypothesis testing... how do you know when to accept/reject null/alternative hypothesis?

[Fatima0065]

(Original post by SugarLips.)
Hi can either of you explain to me the critical value stuff... and when doing hypothesis testing... how do you know when to accept/reject null/alternative hypothesis?

what bits do you wnna know:
When the test statistical(the value you got) is biggere than the critical alue you reject H0
when it is smaller you accept H0

[Fatima0065]

does that make sense?

[SugarLips.]

(Original post by Fatima0065)
does that make sense?

Yes thank you... but is that always the case for all of the hypothesis testing:
like pmcc and spearman's

[abdus110]

(Original post by Fatima0065)
Hello im finding it okai..finally getting the hang of it but i need help on the 6 mark questions for commenting on contribuions after contingency..do you know what to points to write???
and when you use the inverse table how do you know wehn the inverse probability is - or a plus...if that makes sense? thanks for starting this therad..i was jsut gona start buh i saw urs

Hi fatima haha that's my sisters name what a coincidence and yh regarding your question on the 6mark question i knw exactly what ur on a bout first i was a bit uneasy too. what u have to do is first look at the expected and your observed or the contribution is fine, if theyv have given you the contribution
but its much easier if u knw ur expected values, right so what the X^2 test does is measures the difference between the observed and expected and sees how far they were off so say you had an association of the number of birds visiting an area and you were measuring the association between the two if you had an observed vale(what they have given you) of say 50 blue birds visiting the woodland and the expected turned out to be 70.8 say you'd say something like this 'From the observed and expected, there were significantly less blue birds visiting the woodland that expected and so on for each cell in the table and you'll get all you marks refer to the numbers and use the words relatively, significantly ect. a swell as state why as a result of that the contribution is small or large.


hope that helps regarding your other question can u clarify that a bit?

[Fatima0065]

(Original post by SugarLips.)
Yes thank you... but is that always the case for all of the hypothesis testing:
like pmcc and spearman's

Yep...all of them but in PMCC when you have a negative value I have no idea what to do.. ihink you make it positive and see if it is grater than the critical value or not...we'll have to get that chekd

[abdus110]

(Original post by SugarLips.)
Yes thank you... but is that always the case for all of the hypothesis testing:
like pmcc and spearman's

Hi there, no its different for the spear mans and pmcc because you'll get in a exam table a formula book with the critical value and u use that, with the X^2 test you have stuff like degrees of freedom which lead to you obtaining the critical region with the spearmans and pmcc you have separate tables and depending on the size of the sample(n=?) and the significance lever will determine your critical region(as well as whether the correlation had come out negative or positive).

[abdus110]

regarding the positive negative value if u guys have like a sample question post it and ill try give some help

[Fatima0065]

(Original post by abdus110)
Hi fatima haha that's my sisters name what a coincidence and yh regarding your question on the 6mark question i knw exactly what ur on a bout first i was a bit uneasy too. what u have to do is first look at the expected and your observed or the contribution is fine, if theyv have given you the contribution
but its much easier if u knw ur expected values, right so what the X^2 test does is measures the difference between the observed and expected and sees how far they were off so say you had an association of the number of birds visiting an area and you were measuring the association between the two if you had an observed vale(what they have given you) of say 50 blue birds visiting the woodland and the expected turned out to be 70.8 say you'd say something like this 'From the observed and expected, there were significantly less blue birds visiting the woodland that expected and so on for each cell in the table and you'll get all you marks refer to the numbers and use the words relatively, significantly ect. a swell as state why as a result of that the contribution is small or large.


hope that helps regarding your other question can u clarify that a bit?

haha..alot of people have that name.. anywaisz what ur tryna say is that you basiclally compare contributuons see if there is a large or smalle diference btween them and quote numbers for each point..is 3 ppoints enough and for my second question:
you know when they ask you ti find k in a normal distribution and tehy give you a percentage...how do u know if you use a positive or negative sign for the inverse table number. cuz i always get it wrong ..im sorry i dnt know how else to explain it...do u wnat me to get a question...to show what im tring to ask?

[abdus110]

(Original post by Fatima0065)
haha..alot of people have that name.. anywaisz what ur tryna say is that you basiclally compare contributuons see if there is a large or smalle diference btween them and quote numbers for each point..is 3 ppoints enough and for my second question:
you know when they ask you ti find k in a normal distribution and tehy give you a percentage...how do u know if you use a positive or negative sign for the inverse table number. cuz i always get it wrong ..im sorry i dnt know how else to explain it...do u wnat me to get a question...to show what im tring to ask?

ahhh i see what ur on about when they basically give you an value of on the normal distribution which is unkown and your trying to find out that value from the area other curve which theyv said is a certain percentage of the curve and then u do the normal inverse to get that k value. well depending on what tail of the normal curve their asking you to find the value will depend on the sign of it for exam if they said the probability of school boys running times in 5 minutes is normally distributed with mean 22.2 and standard dev 5 and they asked for something like a what is the least value for which a school boy can get to be in the top 5(percent) of running times now that would have to be in the lover tail below the mean cause the time has to be within the top 5(percent ) smallest times so you do 1-0.05 and get 0.95 get the inverse and that k value will have to be negative because its in the lower tail and then solve onwards till you get the actual value remember at the moment its in its standardized from.


hope that helps

[abdus110]

ohh yh id say do every sing cell int eh table and not 3 points then u guaranteed to have hit the 6 marks cause uv said everything which there to be said no no marks lost

[Fatima0065]

(Original post by abdus110)
ahhh i see what ur on about when they basically give you an value of on the normal distribution which is unkown and your trying to find out that value from the area other curve which theyv said is a certain percentage of the curve and then u do the normal inverse to get that k value. well depending on what tail of the normal curve their asking you to find the value will depend on the sign of it for exam if they said the probability of school boys running times in 5 minutes is normally distributed with mean 22.2 and standard dev 5 and they asked for something like a what is the least value for which a school boy can get to be in the top 5(percent) of running times now that would have to be in the lover tail below the mean cause the time has to be within the top 5(percent ) smallest times so you do 1-0.05 and get 0.95 get the inverse and that k value will have to be negative because its in the lower tail and then solve onwards till you get the actual value remember at the moment its in its standardized from.


hope that helps

Yh thannks it makes more sense now...thanks agen btw so sorry i accidentall pressed th thumbs down button on ur post cuz im on an i phone and the buttons are really small im realy sorry nd j

[Fatima0065]

(Original post by abdus110)
ahhh i see what ur on about when they basically give you an value of on the normal distribution which is unkown and your trying to find out that value from the area other curve which theyv said is a certain percentage of the curve and then u do the normal inverse to get that k value. well depending on what tail of the normal curve their asking you to find the value will depend on the sign of it for exam if they said the probability of school boys running times in 5 minutes is normally distributed with mean 22.2 and standard dev 5 and they asked for something like a what is the least value for which a school boy can get to be in the top 5(percent) of running times now that would have to be in the lover tail below the mean cause the time has to be within the top 5(percent ) smallest times so you do 1-0.05 and get 0.95 get the inverse and that k value will have to be negative because its in the lower tail and then solve onwards till you get the actual value remember at the moment its in its standardized from.


hope that helps

Yh thannks it makes more sense now...thanks agen btw so sorry i accidentall pressed th thumbs down button on ur post cuz im on an i phone and the buttons are really small im realy sorry nd just wantd to say ur gona ace this exam got any tips im thinking of doing the past papers again and going thru the questins i dnt understand ... Is ther anything else i cud do???

[Fatima0065]

(Original post by abdus110)
ohh yh id say do every sing cell int eh table and not 3 points then u guaranteed to have hit the 6 marks cause uv said everything which there to be said no no marks lost

Good idea thanks

[abdus110]

(Original post by Fatima0065)
Yh thannks it makes more sense now...thanks agen btw so sorry i accidentall pressed th thumbs down button on ur post cuz im on an i phone and the buttons are really small im realy sorry nd just wantd to say ur gona ace this exam got any tips im thinking of doing the past papers again and going thru the questins i dnt understand ... Is ther anything else i cud do???

haha its okay and yh the best advice i can give is to go through the past papers again like you said and look for the question which they want you to give a wordy answer memorize the mark scheme for that answer cause they can come up again and just practice your normal distribution and possion skills the rest should just come to you naturally and practice more from the book (mei S2) which ur school probably has and you should be alright hopefully and nahhh i doubt it i make silly mistakes in the exam haha

best of luck

[AlexBamsey]

I'm feeling pretty confident, i'm having B's in the past 4 past papers so I'm relatively happy with that!

My main weakness is the poisson and normal, the tricky parts of them, my strongest is probably bivariate and chi squared

[gymrat]

Could someone just run through how to use normal tables exactly? particularly the (add) section towards the far right, my understanding is you 'add' 0.000X, so for z = 1.084, you would get 0.8608? Is that right?

[Fatima0065]

(Original post by abdus110)
haha its okay and yh the best advice i can give is to go through the past papers again like you said and look for the question which they want you to give a wordy answer memorize the mark scheme for that answer cause they can come up again and just practice your normal distribution and possion skills the rest should just come to you naturally and practice more from the book (mei S2) which ur school probably has and you should be alright hopefully and nahhh i doubt it i make silly mistakes in the exam haha

best of luck

Yh thats my plan for today and tmorow...and thanks for the advice... just wanted to say thanks and Good luck with your exam..